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US 4,058,570 AGranted
Brominated biphenol process
AssigneeGeneral Electric Company
InventorsPhilip L. Kinson, Charles M. Orlando
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AssigneeGeneral Electric Company
InventorsPhilip L. Kinson, Charles M. Orlando
Estimating the term…
Brominated biphenols are produced by a bromination process which comprises reacting bromine with a 3,3', 5,5'-tetrasubstituted diphenoquinone at a temperature below about +20.degree. C. in the presence of an inert diluent, evolving hydrogen bromide gas at a temperature of about +20.degree. C. or lower, heating the resulting reaction mixture at elevated temperatures to complete the bromination reaction and recovering the desired 2,2',6,6'-tetrabromo-3,3',5,5'-tetrasubstituted-4,4'-biphenol. The biphenol products of the process can be used as antioxidants, as monomeric starting materials for polymeric halogenated organic compounds which are fire retardant as well as monomeric flame retardant additives for polymeric compositions useful in molding, coating and insulating various articles of manufacture.
An improved bromination process comprising adding at a temperature at least below about +20.degree. C, bromine to 3,3', 4,4'-tetrasubstituted diphenoquinone of the formula ##STR3## wherein independently each R.sub.1, R.sub.2, R.sub.3 and R.sub.4 substituent is selected from the group consisting of primary C.sub.1-8 alkyl, primary C.sub.1-8 alkoxy, phenyl and 4-bromophenyl in the presence of a liquid diluent, evolving hydrogen bromide gas at a temperature of at least about +15.degree. C, heating the resulting reaction mixture at elevated temperatures to complete the bromination reaction, and recovering a 2,2',6,6'-tetrabromo- 3,3',5,5'-tetrasubstituted-4,4'-biphenol, of the formula ##STR4## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are as defined above, and further wherein the yield of the biphenol is at least about 70%.
Dependencies are inferred from the claim text.